The present invention relates to a restriction mechanism for an ignition switch of a vehicle starter switch device.
A vehicle starter switch device includes an ignition rotor, which is held in a cylinder in a rotatable manner. The rotor is rotated to a LOCK position, an accessory (ACC) position, an ON position, or a START position. In accordance with the position of the rotor, in-vehicle devices are activated and inactivated and the engine is stopped and started. More specifically, when the rotor is located at the LOCK position, power is supplied to none of the in-vehicle devices. When the rotor is located at the ACC position, power is supplied to some of the in-vehicle devices such as the audio equipment. When the rotor is located at the ON position, power is supplied to all of the in-vehicle devices. When the rotor is rotated to the START position, the engine is started. When the rotor is rotated from the ON position to the ACC position after the engine is started, the engine is stopped.
The vehicle starter switch device may be of an operation knob type or a key holding type. In an operation knob type switch device, an operation knob, which is coupled to a rotor, becomes rotatable when ID verification is accomplished between an electronic key and a vehicle. In a key holding type switch device, the rotor becomes rotatable when mechanical verification is accomplished by a key hole formed in a rotor and a key inserted into the key hole. The key for the key holding type may be a key blade type mechanical key or a portable electronic key.
For security reasons, the key holding type switch device includes a mechanism that restricts the removal of the key from the key hole at positions other than the LOCK position and a key interlock mechanism that prevents the removal of the key when a gearshift lever is located at a position other than the parking position. The key interlock mechanism, which is used in both types of switch devices, restricts rotation of the rotor to the LOCK position when the gearshift lever is located at a position other than the parking position.
The operation knob type switch device includes a knob lock that restricts rotation of the operation knob from the LOCK position when ID code verification between the electronic key and the vehicle is not accomplished. The knob lock increases the level of security for the vehicle.
Japanese Laid-Open Patent Publication No. 2003-343406 describes a refraction type solenoid knob lock mechanism and an interlock mechanism for a vehicle starter switch device.
The retraction type solenoid knob lock mechanism described in this referential example will now be described. FIG. 11 shows a vehicle starter switch device including an ignition rotor 104, which is arranged in a cylinder 103 and coupled to an ignition switch 105, and an operation knob 102, which rotates the ignition rotor 104. The operation knob 102 is rotated to move the ignition switch 105 to the LOCK, ACC, ON, or START position.
A knob lock mechanism described below permits and restricts rotation of the operation knob 102. Solenoids 106 and 107 are arranged at different locations relative to an axial direction of the ignition rotor 104. As shown in FIGS. 12(a) and 12(b), the solenoids 106 and 107 are arranged with an angular spacing when viewed in an axial direction of the ignition rotor 104. The solenoids 106 and 107, which are of a retraction type, each include a plunger 108. When energized, the plungers 108 project out of the solenoids 106 and 107 against the elastic force of springs 110 and 111.
As shown in FIG. 12(a), a pin hole 114 extends through the ignition rotor 104 in a radial direction. The axis of the pin hole 114 intersects the axis of the ignition rotor 104. A lock pin 115 is accommodated in the pin hole 114. The lock pin 115 includes a step surface 115a that extends perpendicular to the axis of the pin hole 114. The wall defining the pin hole 114 in the ignition rotor 104 includes a step surface 104a corresponding to the step surface 115a. A spring 116 couples the step surface 115a of the lock pin 115 and the step surface 104a of the ignition rotor 104. As shown in FIG. 12(a), in a de-energized state, the elastic force of the spring 116 draws the lock pin 115 from the circumferential surface of the ignition rotor 104 toward the first solenoid 106, and a projecting end of the lock pin 115 is received in a socket formed in the cylinder 103. This engages the lock pin 115 and the cylinder 103 and restricts rotation of the ignition rotor 104.
As shown in FIG. 12(b), when the first solenoid 106 is energized, the plunger 108 pushes the lock pin 115 toward the center of the ignition rotor 104 against the elastic force of the spring 110. The boundary of the plunger 108 and the lock pin 115 conforms to a sheer line between the cylinder 103 and the ignition rotor 104. This disengages the lock pin 115 from the cylinder 103 and allows the ignition rotor 104 to rotate integrally with the lock pin 115. As described above, the knob lock mechanism of the referential example includes the lock pin 115, which is arranged in the ignition rotor 104, and the solenoid 106, which is arranged in the cylinder 103.
With reference to FIG. 13, an interlock mechanism that restricts rotation of the operation knob 102 to the LOCK position will now be described. The second solenoid 107 is arranged on the outer surface of the cylinder 103 at a position corresponding to the ON position to restrict rotation of the ignition rotor 104 to the LOCK position. The ignition rotor 104 has a circumferential surface including a restriction groove 119 extending in the circumferential direction over a predetermined length. The length and the position of the restriction groove 119 are set so that the ignition rotor 104 can be rotated to the ACC position, the ON position, and the START position in a state in which the plunger 108 is arranged in the restriction groove 119. When the solenoid 107 is energized, the plunger 108 projects into the restriction groove 119. In this state, the ignition rotor 104 is rotatable within the range of the ACC position, the ON position, and the START position. However, rotation of the ignition rotor 104 to the LOCK position is restricted. When the solenoid 107 is de-energized, the plunger 108 moves out of the restriction groove 119. This allows the ignition rotor 104 to be rotated to the LOCK position. As described above, the interlock mechanism of the referential example includes the restriction groove 119, which is arranged in the ignition rotor 104, and the solenoid 107, which is arranged in the cylinder 103.
In the referential example, the rotation of the ignition rotor 104 from the LOCK position is restricted when the first solenoid 106 of the knob lock mechanism is de-energized, and the rotation of the ignition rotor 104 to the LOCK position is permitted when the second solenoid 107 of the interlock mechanism is de-energized. This maintains security of the vehicle even when, for example, the solenoids 106 and 107 cannot be energized due to a failure in the electrical system of the vehicle. More specifically, the ignition rotor 104, when arranged at the LOCK position, functions as a steering wheel lock that restricts the rotation of a steering wheel.
Accordingly, the knob lock mechanism restricts rotation of the ignition rotor 104 from the LOCK position when the solenoids 106 and 107 are de-energized. Thus, the steering wheel lock keeps the steering wheel locked when a failure occurs in the electrical system.
Further, when the ignition rotor 104 is arranged at a position other than the LOCK position and the solenoids 106 and 107 are de-energized, the ignition rotor 104 is allowed to rotate to the LOCK position. Accordingly, the rotor 104 is rotatable to the LOCK position even when a failure occurs in the electrical system. In the key holding type switch device, this allows for removal of the key when the ignition rotor 104 is rotated to the LOCK position.